No fetal cardiac during 2nd scans

Hi,its my first pregnancy. I was at 5 weeks pregnant when we did a scan at kkh and theres a heart beat A week later i had a mild cramps, being worried and scared we went to the EPAU . Did a scan and to my horror no fetal cardiac was detected. The gynea at kkh got us to come back again at our original appointment which is two weeks later to get it scan again . Any of other pregnant moms experiencing the same thing before ? Will the fetal cardiac detected again ? #worried